Research on Performance Evaluation and Optimization of Composite Insulators in High-Altitude Strong Ultraviolet Environment

With the advancement of railway construction into high-altitude regions, high-voltage traction power supply systems face growing challenges from harsh environmental conditions. Intense ultraviolet (UV) radiation in these areas accelerates the aging of external insulation materials, posing serious risks to operational safety. In this study, an accelerated UV aging test platform was established, and an equivalent aging method was developed based on total radiation to simulate long-term natural exposure. Standard silicone rubber materials were subjected to 1,000 h of accelerated aging, equivalent to over 10 years of field aging. From 22 performance parameters, 12 key indicators were selected to assess mechanical, electrical, and physicochemical degradation. By optimizing material composition and incorporating UV inhibitors, the improved samples exhibited significantly enhanced aging resistance. A comparative analysis was further conducted to estimate the service life of each formulation under varying UV intensities. The findings offer practical guidance for improving the durability of external insulation in traction power supply systems and contribute to ensuring the long-term safety and stability of railway operations in high-altitude, high-UV environments.